Upper row: ¹³CO integrated intensity including emission from the full cloud. Bottom row: integrated intensity of the full ¹³CO (upper row) masked by a ¹³CO synthetic observation of the tracer field to obtain the pixel locations of the feedback in PPV space (see Section 2.3.2). First column: synthetic observations corresponding to model W2_T2_t0 in Offner & Arce (2015). Second column: synthetic observations corresponding to model W2_T2_t1. Third column: synthetic observations corresponding to model W1_T2_t0. Fourth column: synthetic observations corresponding to model W2_T3_t0.